This invention relates to an apparatus for transporting food products, from a station whereto they are delivered one after the other, to a second station whence at least two of said products are simultaneously picked up and passed over to subsequent processing.
It is known that in a process for packaging food products which have peculiar features of texture, shape, and dimensions--as may have certain confectionary products, bakery products, and the like--a fairly common practice is to first package each product individually, and then pack (or box) the individually packaged products in predetermined numbers, for example within a common box or such like container.
Packaging lines for products as above are, therefore, equipped with two packaging machines which have, of necessity, different constructional and performance characteristics and which, above all, operate at different rates: the machine which packages the individual products being the faster of the two, and the machine which boxes the predetermined numbers of individually packaged products being the slower.
For creating no discontinuities in the production line (storage or lack of products at some key points along the line), as well as to ensure an at least acceptable productivity from the industrial standpoint, the operational times and rates of the two packaging machines, the slow one and the fast one, must be disjoined and made independent of each other.
For this purpose, an apparatus has long been in use for transporting individually packaged food products from the fast packaging machine to the slow one, which apparatus comprises a continuous belt entraining a series of substantially tray-like containers along a closed loop path. The containers are halted at a first station where they are each loaded with a single packaged product and then halted at a second station to form groups of a predetermined number of said containers whence the respective packaged products are simultaneously picked up and taken to the slow packaging machine. Throughout this specification and the appended claims, said first station will be referred to as the load station for loading individually packaged products and the second station as the unload station for simultaneously unloading a predetermined number of such products.
Each container is provided with a hitch mechanism that clasps elastically the belt, whereby it is entrained in frictional engagement with the latter. At the load and unload stations, the container is halted by check devices which hold up the container against said frictional engagement, while the belt continues to run in order to move non-halted containers located in areas other than the load and unload stations.
It is a recognized fact that the adjustment of the friction force to enable proper operation of the transport apparatus constitutes a problem. In fact, a sufficiently large friction force is required to prevent relative slip between the hitch mechanism and the belt while the belt is dragging the container with it, so as to avoid losses of speed by the container; on the other hand, the friction force should be sufficiently small not to strain the check devices and harm the belt when the container is held up at the load and unload stations. Any solution is, therefore, a compromise solution which fails to provide a highly efficient transport apparatus.
In addition, the friction force may change over time and require renewed setting of the transport apparatus.